Automatically locking slider for slide fasteners

ABSTRACT

An automatic slider lock mechanism including a locking leaf spring arranged longitudinally over the top wing of the slider body. The locking leaf spring is slitted longitudinally to be divided into a central strip and a pair of side strips which are all interconnected at the front end of the spring. Two pairs of spring retainers are formed on the top wing of the slider body to engage the side strips only of the locking leaf spring. The central strip has a locking pawl at its rear end which normally extends downwardly over the rear end of the top wing into the guide channel in the slider body. The pull tab of the slider surrounds at one end the locking leaf spring in such a manner that the locking pawl retracts away from the guide channel only when there is a pull on the pull tab.

United States Patent [191 Fukuroi AUTOMATICALLY LOCKING SLIDER FOR SLIDE FASTENERS [75] Inventor: Takeo Fukuroi, Uozu, Japan [73] Assignee: Yoshida Kogyo Kabushiki Kaisha,

Tokyo, Japan [22] Filed: Jan. 30, 1975 [21] Appl. No.: 545,360

[30] Foreign Application Priority Data Feb. 7, 1974 Japan 49-15866[U] 52 us. ci... 24/20s.14 R 51 Int. cl. A44B 19/30 58 Field of Search 24005.14 R

[56] 1 References Cited UNITED STATES PATENTS 3,016,592 l/l962 Manning 24/205.14 R

TVl 21 Nov. 18, 1975 Primary Examiner-Bernard A. Gelak Attorney, Agent, or Firm-Bucknam and Archer [57] ABSTRACT An automatic slider lock mechanism including a locking leaf spring arranged longitudinally over the top wing of the slider body. The locking leaf spring is slitted longitudinally to be divided into a central strip and a pair of side strips which are all interconnected at the front end of the spring. Two pairs of spring retainers are formed on the top wing of the slider body to engage the side strips only of the locking leaf spring. The central strip has a locking pawl at its rear end which normally extends downwardly over the rear end of the top wing into the guide channel in the slider body. The pull tab of the slider surrounds at one end the locking leaf spring in such a manner that the locking pawl retracts away from the guide channel only when there is a pull on the pull tab.

4 Claims, 4 Drawing Figures Ill H v2O1 20 M US. Patent Nov. 18, 1975 FIG! FIG. 3

FIG-4 I turely'.

LOCKINGSLIDER FOR SLIDE FASTENERS BACKGROUND or TIIIz f NvENTIoN This invention relates generally to slide fasteners and more specifically to an automatically locking slider for slide fasteners. Even more specifically, the invention is directed to an'automatic slider lock mechanism of the type including a leaf spring arranged longitudinally over the slider body and-having a locking pawl at one end which normally is urged into interference contact with rows of interlocking" fastener elements passing through the slider body to-lock the slider against movement thereon and which retracts out of contact therewith to unlock the slider when a pull is exerted on the pull tab of the slider. I

,Inthe known automatic'slider-lock mechanism of the type now under-consideration,- the-locking leaf spring is usually aff xed to the' to'p wing' of-the slider body at its front end portion only. The spring supported in this manner 'is rather insecure compared" 'v'vith'the springs usedin other types of automaticallylocking sliders.

The locking leaf spring suppdrte'ld iii'tlfeconventional manner is also objectionable in "tha itsfeffe'ctive length, that is, the length between'its lo'c "n g pawl and that point of the spring where i t' is secured tc ith e" slider body, is short asconsidered from the standpointof invention.'Th'e elasticity 'ofsuch'spring tends to diminish to such an extent'before expiration of the expected lifetime of the'co' mplete slide fastener that the auto matic lock mechanism "wiIlbe'come inoperable preri a- AUTOMATICALLY 'vention" iiirewar; an im- It is aniobject ofithi" I proved automatic r'riechanisni "for "the sliders of .slidefasteners which includes a locking ,leaf spring so configured and mounted "on the slider body as to preclude practically anypossibility' of displacement ordetachment. II i Another object of the invention:

provide an automatic slider lock mechanism where n, thelock ing leaf spring has a far greater effective length than the springs used in the prior art lock mechanisms of comparable classQthereby contributing materially toward the longer service life and more positive, efficient performance of the mechanism according to the invention,

With these and other objects in view, this invention -provides, in a slide fastener sliderof the well known type, an automatic lock mechanism including a locking leaf springgenerally arranged longitudinallyoverthe top wing of the, slider body. A pair of parallel spaced slits are formed lengthwise in the locking leaf spring to divide the same into a central strip and a pair, of side strips, thethree strips being all interconnected ,at the front end of thelocking leaf spring. The locking spring is supported in position on the slider body by spring re-. taining means on its top wing adapted to engage the side strips only of the spring. The central strip of the locking leaf spring has a portion extending rearwardly of the side strips to provide a locking pawl which normally projects into the usual guide channel in the slider body for interference contact with rows of interlocking fasteners elements passing therethrough. The central strip also includes a raised portion intermediate both ends thereof which is adapted to be surrounded by the pull tab of the slider, in such a manner that the locking pawl moves out of interference contact with the fastenerelements when a pullis exerted on the pull tab. According to a preferred-embodiment of the inventionherein disclosed, the spring retaining means comprises a pair of spring retainers formed rather closer to the front end of the slider body to engage the outer edge portions of the respective side strips of the locking leaf spring, and another pair of spring retainers formed adjacent the rear end of the slider body to engage the rear end portions of the respective side strips. With its side strips thus engaged by the four spring retainers, the locking leaf spring is far more stably supported in the slider body than the springs of the prior art mechanism which have been secured to the slider body at their front end portions only.

Furthermore, since the central strip of the locking leaf spring is not engaged by the spring retaining means, the aforesaid effective length of the spring is far greater than that of the springs of the prior'art mechanisms. The elasticity of the spring will remain constant for an extended length of time, so that the automatic lock mechanismaccording to the invention is highly endurable, functioning efficiently throughout the life expectationof the complete slide fastener.

.The featureswhich are believed to be novel and characteristic of this invention are set forth in particular in the claims appended hereto. The invention itself, however, both .as to its construction and mode of operation, together ,;;with the further objects and advantages thereof, will become apparent in the course of the following description of the preferred embodiment, which is to be read in connection with the accompanying drawings in which like reference characters refer to like parts throughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 is also a sectional view taken along the plane of line IV-IV in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated in FIGS. 1 and 2, the slider for use with the automatic lock mechanism according to the invention can be of thewell known type comprising a body 10 and a pull tab 11. The slider body 10 has a flared front end 12 and a contracted rear end 13 and is comprised of a top wing 14 and a bottom wing 15. The top and bottom wings l4 and 15 have flanges 16 along their marginal edges and are interconnected by a web or neck 17 located centrally at the flared front end 12 of the slider body 10. The usual Y-shaped guide channel is thus formed through the slider body. 10 to permit rows of interlocking fastener elements, not shown, to pass therethrough asthe slider is moved therealong to open or close the slide fastener.

The automatic lock mechanism according to the invention, shown in its preferred form in the drawings, includes a locking leaf spring 18 generally arranged longitudinally over the top wing 14 of the slider body 10. The locking leaf spring 18 has a pair of parallel spaced slits 19 formed lengthwise therein. The slits 19 extend from the rear end of the locking leaf spring 18 and terminate short of its front end. Enlarged portions 20 may be formed at the front extremities of the respective slits 19.

As will be best understood from a consideration of FIG. 1, the slits 19 are intended to divide the locking leaf spring 18 into a central strip 21 and a pair of identical side strips 220 and 22b flanking the central strip. These strips 21, 22a and 22b, of course, are interconnected at the front end of the locking leaf spring 18.

Projecting upwardly from the top wing 14 of the slider body 10 are a pair of transversely spaced spring retainers 23a and 23b, which are located rather closer to the flared front end 12 of the slider body, and another pair of transversely spaced spring retainers 24a and 24b which are located adjacent the contracted rear end 13 of the slider body. The spring retainers 23a and 23b are arranged on both sides of the locking leaf 18 to engage the outer edge portions of the respective side strips 22a and 22b, whereas the other spring retainers 24a and 24b engage the rear end portions of the respective side strips, as shown in FIG. 1 and in greater detail in FIGS. 3 and 4. The locking leaf spring 18 is thus securely supported in position on the slider body 10.

The central and side strips 21, 22a and 22b of the locking leaf spring 18 have raised portions 25, 26a and 26b, respectively, which are arranged in transverse alignment between the pairs of spring retainers 23a and 23b, and 24a and 24b. It will be noted from FIGS. 1 and 2 that the raised portion 25 of the central strip 21 is of greater extent than the raised portions 26a and 26b of the side strips 22a and 22b. Thereis arranged between the raised portions 25, 26a and 26b of the locking leaf spring 18 and the top wing 14 of-the slider body 10 a pin 27 extending between the tips of a pair of prongs 28 at the bifurcated end of the pull tab 11. The pin 27 has a protuberance 29 in its mid-portion extending in the general plane of the pull tab 11 for slidable engagement with the raised portion 25 of the central strip 21.

The central strip 21 of the locking leaf spring 18 has a portion extending rearwardly of the side strips 22a and 22b. This portion is adapted to provide a locking pawl 30 which extends downwardly over the rear end of the top wing 14, normally for interference contact with the unshown rows of fastener elements passing through the Y-shaped guide channel in the slider body Thus, when a pull is exerted on the pull tab 11 surrounding the locking leaf spring 18 at one end thereof to move the slider along the rows of interlocking fastener elements in either direction, the protuberance 29 of the pin 27 at the bifurcated end of the pull tab becomes held at a certain angle to the plane of the top wing 14 of the slider body 10. As a consequence, the raised portion 25 of the central strip 21 of the locking leaf spring 18 is lifted away from the top wing 14, so that the locking pawl at the rear end of the central strip moves out of interference contact with the fastener elements as it retracts away from its normal position best illustrated in FIG. 2. The slider, now unlocked, is free to move along the rows of fastener elements as long as there is a pull on the pull tab 11. When the pull tab is released, the locking pawl 30 again projects into the guide channel in the slider body to re-engage the fastenerelements passing therethrough and hence to lock the slider against movement in the desired position on the pair of fastener stringers.

Having thus described the automatically locking slider according to the invention, it is clear that the objects as above stated, either explicitly or otherwise, have been accomplished in a simple and practical manner. However, while the invention has been shown and described herein in terms of but one of its various possible adaptations, it is to be understood that changes may be made in the construction and arrangement of the various parts of the illustrated slider, without necessarily departing from the spirit and scope of the invention as expressed in the following claims.

What is claimed is:

1. In a slide fastener slider of the type having a pull tab and a body and a locking means, said slider body including a top wing and a bottom wing which are interconnected by a web located centrally at the front end of said slider body so as to define a generally Y-shaped guide channel therethrough, an automatic lock mechanism comprising, in combination, a locking leaf spring generally arranged longitudinally over said top wing of said slider body, said locking leaf spring having a pair of parallel spaced slits extending lengthwise from its rear end and terminating short of its front end whereby said locking leaf spring is divided into a central strip and a pair of side strips which are interconnected at the front end of said locking leaf spring, and spring retaining means on said top wing of said slider body adapted to engage said side strips of said locking leaf spring to retain the latter on said slider body, said central strip of said locking leaf spring having a portion extending rearwardly of said side strips to provide a locking pawl which normally projects into said guide channel in said slider body, said central'strip of said locking leaf spring also having a raised portion intermediate both ends thereof which is adapted to be surrounded by said pull tab in such a manner that when a pull is exerted on said pull tab, said central strip is generally raised away from said slider body whereby said locking pawl retracts away from said guide channel in said slider body.

2. The automatic slider lock mechanism as recited in claim 1, wherein said spring retaining means comprises a first pair of spring retainers formed on said top wing adjacent the front end of said slider body to engage the outer edge portions of said side strips, respectively, and a second pair of spring retainers formed on said top wing adjacent the rear end of said slider body to engage the rear end portions of said side strips, respectively.

3. The automatic slider lock mechanism as recited in claim 2, wherein said side strips also have raised portions, respectively, which are arranged in transverse alignment with said raised portion of said central strip between said first and second pairs of spring retainers, and wherein said pull tab has a pair of prongs at one end and a pin extending between the tips of said prongs, said pin being arranged between said top wing and said raised portions of said central and said side strips and having protuberance extending in the plane of said pull tab, said protuberance being adapted for slidable engagement with said raised portion of said central strip.

4. The automatic slider lock mechanism as recited in claim 3, wherein said raised portion of said central strip is of greater extent than said raised portions of said side strips. 

1. In a slide fastener slider of the type having a pull tab and a body and a locking means, said slider body including a top wing and a bottom wing which are interconnected by a web located centrally at the front end of said slider body so as to define a generally Y-shaped guide channel therethrough, an automatic lock mechanism comprising, in combination, a locking leaf spring generally arranged longitudinally over said top wing of said slider body, said locking leaf spring having a pair of parallel spaced slits extending lengthwise from its rear end and terminating short of its front end whereby said locking leaf spring is divided into a central strip and a pair of side strips which are interconnected at the front end of said locking leaf spring, and spring retaining means on said top wing of said slider body adapted to engage said side strips of said locking leaf spring to retain the latter on said slider body, said central strip of said locking leaf spring having a portion extending rearwardly of said side strips to provide a locking pawl which normally projects into said guide channel in said slider body, said central strip of said locking leaf spring also having a raised portion intermediate both ends thereof which is adapted to be surrounded by said pull tab in such a manner that when a pull is exerted on said pull tab, said central strip is generally raised away from said slider body whereby said locking pawl retracts away from said guide channel in said slider body.
 2. The automatic slider lock mechanism as recited in claim 1, wherein said spring retaining means comprises a first pair of spring retainers formed on said top wing adjacent the front end of said slider body to engage the outer edge portions of said side strips, respectively, and a second pair of spring retainers formed on said top wing adjacent the rear end of said slider body to engage the rear end portions of said side strips, respectively.
 3. The automatic slider lock mechanism as recited in claim 2, wherein said side strips also have raised portions, respectively, which are arranged in transverse alignment with said raised portion of said central strip between said first and second pairs of spring retainers, and wherein said pull tab has a pair of prongs at one end and a pin extending between the tips of said prongs, said pin being arranged between said top wing and said raised portions of said central and said side strips and having protuberance extending in the plane of said pull tab, said protuberance being adapted for slidable engagement with said raised portion of said central strip.
 4. The automatic slider lock mechanism as recited in claim 3, wherein said raised portion of said central strip is of greater extent than said raised portions of said side strips. 